40 - 3
Section E
Hydraulics
9803/6400
Section E
40 - 3
Issue 1
Remote Control Valve JS200/JS240
Operation
The structure of the pilot valve is shown in the assembly drawings (see previous page). The pressure reduction valve unit is
built into the vertical bore in the casing.
The pressure reduction unit consists of the spools (201), secondary pressure setting springs (241), return springs (221),
washers 1 (215), spring seats (216) and washers 2 (217). The secondary pressure setting springs are set to give a secondary
pressure of 5~24 kgf/cm 2 (depending on the model). The spools are pressed against the push rods (212) by the return springs.
When the handle is tilted, the push rods are forced down, pushing down the spring seats, to adjust the setting of the secondary
pressure setting springs. An oil inlet (primary) port P and oil outlet (tank) port T are provided in the casing. In addition,
secondary outlet ports 1,2,3 and 4 are situated on the lower surface of the casing.
Basic Functions
The pilot valve controls the stroke and direction, etc. of the control valve spool. This is achieved by providing a spring at one
end of the control valve spool and applying the output pressure of the pilot valve to the other end. (There is also the method
where the pilot valve output pressure is used on both ends of the control valve).
In order to provide this function, the pilot valve consists of the following:
1.
Inlet port (P) which is supplied with oil from the pump.
2.
A number of outlet ports (1,2,3,4) to supply the pressure from the inlet port to control valve spools.
3.
Tank port (T), required to control the pressure output from 2.
4.
Spools to connect the outlet ports to the inlet port and tank port.
5.
Mechanism, including springs, to control the spools in 4 above.
Functions of the Major Parts
Oil supplied by the hydraulic pump is received by P port and the function of the spool (201) is to switch the pressurised oil from
the inlet port P to the output port (1, 2, 3, 4) or alternatively, from the output port to the tank port (T). The springs (241) act on
the spools and determine each outlet pressure. The push rods (212) are able to slide in the plugs (211) to adjust the
compression of the springs. The handle acts through the disk (302) and adjusting nut (312) to move the push rods. The handle
is able to rotate a full circle around the joint (301).
The springs (221) operate against the casing (101) and the spring seats (216) act, regardless of the outlet pressure, to return
the push rods to their natural position, thus ensuring that the spools return to their neutral position. This spring also provides a
resistive force which gives the controls a suitable "feel" to the operator.
Summary of Contents for JS 200 Series
Page 57: ...9 1 Section 3 Routine Maintenance 9803 6400 Section 3 9 1 Issue 2 Component Location Diagram...
Page 113: ......
Page 137: ...5 3 Section C Electrics 9803 6400 Section C 5 3 Issue 2 Pump Control FLOW CHART...
Page 201: ...10 7 Section C Electrics 9803 6400 Section C 10 7 Issue 1 CAPs II Diagnostic system K C...
Page 215: ...Section E Section E Hydraulics 9803 6400 Issue 2 3 2 3 2 Schematics...
Page 217: ...Section E Section E 9803 6400 Issue 2 3 3 3 3 Hydraulics Schematics...
Page 218: ...3 5 Section E Hydraulics 9803 6400 Section E 3 5 Issue 1 Schematics Shuttle Block JS200 JS240...
Page 232: ...10 1 Section E Hydraulics 9803 6400 Section E 10 1 Issue 1 Hydraulic Pump JS200 JS240...
Page 233: ...10 2 Section E Hydraulics 9803 6400 Section E 10 2 Issue 1 Hydraulic Pump JS200 JS240...
Page 234: ...10 3 Section E Hydraulics 9803 6400 Section E 10 3 Issue 1 Hydraulic Pump JS200 JS240...
Page 263: ...30 2 Section E Hydraulics 9803 6400 Section E 30 2 Issue 1 Control Valve JS200 JS240...
Page 264: ...30 3 Section E Hydraulics 9803 6400 Section E 30 3 Issue 1 Control Valve JS200 JS240...
Page 265: ...30 4 Section E Hydraulics 9803 6400 Section E 30 4 Issue 1 Control Valve JS200 JS240...
Page 266: ...30 5 Section E Hydraulics 9803 6400 Section E 30 5 Issue 1 Control Valve JS200 JS240...
Page 267: ...30 6 Section E Hydraulics 9803 6400 Section E 30 6 Issue 1 Control Valve JS200 JS240...
Page 268: ...30 7 Section E Hydraulics 9803 6400 Section E 30 7 Issue 1 Control Valve JS200 JS240...
Page 327: ...51 12 Section E Hydraulics 9803 6400 Section E 51 12 Issue 1 Solenoid Valve 8 spool...
Page 328: ...55 1 Schematic Section E Hydraulics 9803 6400 Section E 55 1 Issue 1 Shuttle Valve...
Page 330: ...55 3 Schematic Section E Hydraulics 9803 6400 Section E 55 3 Issue 1 Cushion Valves...
Page 481: ...7 15 Section F Transmission 9803 6400 Section F 7 15 Issue 2 Motor...
Page 482: ...7 16 Section F Transmission 9803 6400 Section F 7 16 Issue 1 Motor...